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Show CURIOUS FACT LITTLE KNOWN But It is Easily Possible for One to Boil and Freeze Water at the Same Time. It is a curious fact that water may be. boiled and frozen at the same time. The temperature at which water boils depends simply upon the air pressure upon its surface. If there be a high pressure, the water must be rendered a good deal "hotter in order that it may boil than would be the case at a low pressure. In mountainous regions, where the air pressure is a good deal lower than at sea level, water boils - easily at a low temperature. In cooking vegetables vege-tables that require a certain degree of heat, when the water boils before that degree of heat is attained, ihe vegetables vege-tables will "not get done." Consev quently, they must be placed in a closed boiler, so that the generated steam will create sufficient pressure for the water to boil at or beyond the required temperature. In the experimental proof of this fact the water is placed in a vessel and the air is exhausted frSm above the surface of the water. As the process proc-ess of -pumping continues the water will boil violently, the steam congealing congeal-ing on the sides of the exhaust vessel. If the pumping is continued for a sufficient suf-ficient period, and the outside is cooled btl nv the freezing point, the water will continue to boil and bubble until it is frozen into a snowy mass of ice. The fact is utilized in the estimation of the height of mo m'.ains. Ordinarily at sea level, where the pressure is about 30 inches of mercury, water boils at 212 degrees Fahrenheit. Now, if it is noticed that at a certain place' it boils a few degrees lower, the height of that place may be easily ascertained by the comparison with a table made out for this purpose. In general, for every degree the boil ing takes place under 21 2,-a height of about 500 feet is counted. . This principle prin-ciple does not, of course, apply to water wa-ter alone, but is characteristic- of all liquids. |